(1) Field of the Invention
The present invention relates to chlorinated ethylene-.alpha.-olefin copolymer rubber and composition thereof. More particularly, the present invention relates to chlorinated ethylene-.alpha.-olefin copolymer rubber which has excellent processibility, heat resistance, and rubber elasticity, and is very useful for extending the service life of rubber products and compositions of said copolymer rubber.
(2) Description of the Prior Art
Chlorinated ethylene-.alpha.-olefin copolymer is already known. For example, it is disclosed in Rubber Chem. Technol. 49 353 (1976), Japanese Laid-Open Application No. 60-99149, and Japanese Laid-Open Application No. 1-182340. Although the aforementioned conventional chlorinated ethylene-.alpha.-olefin copolymer rubber is a rubber excelling in ozone resistance and heat aging resistance, it poses problems such that one having a high vulcanization speed is inferior in heat resistance, while another having good heat resistance gives a low vulcanization speed, hence poor processibility, and a poor rubber elasticity.